Photovoltaic cell with enhanced power output

Abstract

The photovoltage and photocurrent, and therefore, the power output of photovoltaic cells (solar cells) are markedly enhanced by depositing, on an exposed semiconductor surface of a solar cell, a layer of any one of a very large number of prophyrinic compounds.

I claim: 
     
       1. An article of manufacture comprising a photovoltaic cell having a layer of at least one porphyrinic compound deposited on an exposed semiconductor surface thereof, said layer being at least as thick as a monomolecular layer of said porphyrinic compound. 
     
     
       2. An article as claimed in claim 1 wherein the photovoltaic cell is a selenium cell. 
     
     
       3. An article as claimed in claim 1 wherein the photovoltaic cell is a Cu/CuO cell. 
     
     
       4. An article as claimed in claim 1 wherein the photovoltaic cell is a silicon cell. 
     
     
       5. An article as claimed in claim 1 wherein the porphyrinic compound is a compound containing the porphin structure: ##SPC2## 
     
     
       6. An article as claimed in claim 1 wherein the porphyrinic compound is selected from the group consisting of tetraphenyl porphyrin, zinc octaethyl porphyrin, copper tetraphenyl porphyrin, zinc tetraphenyl porphyrin, magnesium tetraphenyl porphyrin, iron tetraphenyl porphyrin chloride, silver tetraphenyl porphyrin, tetra-n-propyl porphyrin, porphin, tintetraphenyl porphyrin dichloride, tetraphenylchlorin TPPH 2 .sup. +2  (TFA - ) 2 . 
     
     
       7. A method of producing the article of claim 1, comprising depositing on an exposed semiconductor surface of a photocell, a layer of at least one porphyrinic compound, said layer being at least as thick as a monomolecular layer of said porphyrinic compound. 
     
     
       8. A method as claimed in claim 7 wherein the thickness of the layer is from 0.003 up to one micron. 
     
     
       9. A method as claimed in claim 7 wherein the photocell is a selenium, silicon or Cu/CuO cell. 
     
     
       10. A method as claimed in claim 7 wherein the porphyrinic compound is a compound containing the porphin structure: ##SPC3## 
     
     
       11. A method as claimed in claim 7 wherein the porphyrinic compound is selected from the group consisting of tetraphenyl porphyrin, zinc octaethyl porphyrin, copper tetraphenyl porphyrin, zinc tetraphenyl porphyrin, magnesium tetraphenyl porphyrin, iron tetraphenyl porphyrin chloride, silver tetraphenyl porphyrin, tetra-n-propyl porphyrin, porphin, tintetraphenyl prophyrin dichloride, tetraphenylchlorin TPPH 2 .sup. +2  (TFA - ) 2 . 
     
     
       12. A method as claimed in claim 7 wherein the photocell is a silicon cell and the method further comprises treating the cell with an alcoholic KOH solution to convert silicon dioxide on the surface of said cell to silica gel and diffusing the porphyrinic compound through said silica gel and onto the silicon semiconductor surface. 
     
     
       13. An article as claimed in claim 1, wherein the thickness of the layer is from 0.003 to 1 micron.